Outboard engine cooling device



Feb. 4, 1947. Q WALTER 2,415,154

OUUTBARD ENGINE COOLING DEVICEv Filed Nov. 26, 1943 5 Sheets-Sheet l J4 flo o nl' o uli O o l 47 W 461 z@ ff f2.7' Z zz f II llllllllmnllm; f.; lglmlllllklhlllllllnm W Wi 1 mi lI 7 f uw. 1 j) ff 4f III-5J Feb. 4, 1947.' G. WALTER 2,415,154

OUTBOARD ENGINE COOLING DEVICE Filedwlov.y 26, 1943 3 Sheets-Sheet 2 ll-II 4 if l IafIIIIIW :inventor @Mfr Feb. 4, 1947. G, WALTER i 2,415,154

OUTBOARD ENGINE COOLING VDEVICE Filed'Nov. 26, 1943 3 Sheets-Sheet 3 VELEZ-vn,

Snnentor Patented Feb. 4, 1947 UNITED STATES PATENT oF FICE The present invention relates to improvements in outboard engine cooling device, and consti` tutes certain improvements over my prior invention as disclosed in my prior Patent No. 2,258,526, granted October 7, 1941.

The present invention has for its purposes and objects, those set forth in my prior patent aforesaid, in addition to those hereinafter set forth.

It is an object of the present invention to increase the cooling capacity of the prior device and thereby to enhance the effectiveness of the device as a heat exchanger in cooling the engine jacket water; this to the end of preventing overheating of the engine and the incidental damage and disasters resulting therefrom.

In outboard motor coolers the problem of increasing heat exchangecapacity cannot be directly and immediately solved by mathematical enlargement of the volume capacity of the cooler, for the reason that the external placement of the cooler with respect to the boat hull interposes a drag element and an increase in skin friction which cannot be enlarged in area without proportionately reducing speed and maneuverability performance factors of the boat at such a ratio that the material enlargement of the cooler area is prohibited.

A further object of the invention is to overcome and solve this problem in the production of an external cooling assembly which will possess the necessary volumetric capacity but which is so constructed and arranged relatively to the hull and keel of the boat and to the various members of the cooler assembly as to retain the drag and skin friction factors Within a minimum so as not to interfere in any substantial way with the effective speed of the boat and its maneuverability.

A further object of the invention is to provide an improved cooler` unit and assembly in combination with an improved inlet and outlet assembly which results in the delivery of the incoming water simultaneously to a plurality of small diameter tubes, the inlet and outlet unit also being so constructed and arranged as to accommodate the eiuent by withdrawing the same simultaneously from a plurality of such tubes.

A still further object of the invention resides in providing an improved form of terminal header fitting in which the rate of ow of the water to and from all of the cooling tubes will be substantially uniform, thus avoiding stagnation Zones which interfere with the uniformity of flow rate and correspondingly decrease the cooling effect of the unit as a whole.

With the foregoing and other objects in View,

theinvention will bemore fully described here'-` inafter, and will be more particularly pointed out in the claim appended'hereto. In the drawings, wherein like symbols refer to like or corresponding parts throughout the several views, i

Figure 1 is a side elevation, with parts broken away and parts shown in section of an improved outboard engine cooling deviceconstructed in ac.. cordance with the present invention, and shown as applied to a boat hull or keel indicated in' broken lines. Figure 2 is a horizontal section takenon the line 2-2 in Figure 1 with the intermediate portions of the tubes broken away and with the inlet and outlet unit omitted.` Figure 3 is a bottom plan view, with parts broken away and parts shown in section of the device of Figure 1. Figure 4 is a vertical section taken on the line 4-4 in Figure 2.

Figure 5 is also a vertical section taken on the line 5 5 in Figure 2,.

Figure 6 is a perspective View, partly broken away and partly shown in section,` of one of the improved terminal header fittings. Figure 7 is a similar View taken through an?` other chamber of the terminal headeriitting.

Figure '7a is a horizontal cross-section taken through the left header of Figure'z through the lower passage. Figure 7b is a longitudinal section through the header. Figure 8 is a vertical transverse section taken on the line 8-8 in Figure 1. Figure 9 is a top plan view of the inlet and outlet thermostatic cap.

Figure l0fis a view similarto ing a modification.

Figure 11 is a bottom shown in Figure 10. g

Figure 12 is a transverse vertical` section taken on the line IZ-IZinFlgure 10, and L Figure13 is a top plan view of the inlet and outlet cap, partly broken away and partly shown in section. d Referring more particularly to the drawings, and for the present to Figures 1 to 9 inclusive, l5 shows in broken lines the hullor keel of `a boat to which the device may be secured in any suit-Y able manner, as for instance shown and described in my prior patent aforesaid.

Figure 1 but showplan View of 'the device:

The external unit or cooler assembly is, in this"` particular embodiment of the invention, made up of four copper or other tubes I6, I1, I8 and y I9 of relatively small diameter so as to be susceptible of close grouping with respect to one another and of fitting closely against the external skin of the keel or hull I to avoid a bulky enlargement. The opposite ends of the four tubes are fitted in the terminal header ttings and 2|. These headers 20 and 2| are secured to the hull or keel I5 by means of end clamps 22 and 23. Intermediate clamps 24 and 25 serve to support the tubes. Bolts 26 secure the clamps lto the hull or keel I5; or any other fastenings scribed in my prior patent aforesaid, Awith the exception that, as shown in Figure 3, the two chambers of the standpipe 21 at opposite sides of the partition 30 have cross-sectional capacity substantially equal to that of two of the tubes of the cooling unit so that `the inlet `chamber 39 mayV communicate simultaneously with two of the tubes, for instance, the tubes I6 and I1 for the simultaneous delivery thereto of the incoming hot water from the water jacket -of the engine installed to drive the boat. This engine is not .shown herein but its relative connection with the stand pipe is fully disclosed in my prior patent aforesaid. In a similar way the outlet chamber 4I) at the other side of the partition 3l] communicates simultaneously with the two tubes I6 andI1 at the lother side of the base ittiner 29.

A plate `4I of the base fitting 29 engages the hull I5 and is formed with openings 42 to receive the bolts 32 by which the base fitting 29 is held to the hull I5. The bolts 3.2 pass through an inside plate `3l which is perforated to surround the stand pipe 21. A washer and nut assembly 33l istted to the externally threaded .stand -pipe 21 and bears upon the inside plate 3|. The `stand pipe and its base tting 29 constitute a combined inlet and youtlet fitting coordinated in one -element which therefore requires only the one opening 28 through the hull I5 to set up communication with the external cooler and the internal engine water` jacket.

The outlet cap or thermostatic head -34 may be similar to that shown and described in my prior patent aforesaid and may be held onto the stand pipe by bolts 43 according to the construction more particularly shown in such prior patent.

Referring more particularly to Figures 2, 4, 5, 6 and 7, the improved terminal header 20 may conveniently be made from a casting of metal or other suitable material in which 35 designates the top wall,v 36 the bottom wall and 31 and 38 the front and rear walls respectively. This casting is coredoutto provide passages for .rece1ving and reversing the flow of thet water.

- As shown in Figure 2 an end wall 44 cooperates with a septum or partition to create a substantially (Jr-shaped passage or chamber 46 placing the left ends of tubes I6 and I8 in communication. In other words water flowing as indicated by the arrow in Figure 2 toward the left in end tube I6 will enter passage 46, wherein its direction of flow will be reversed, and directed outwardly through intermediate tube I8, through which the water will traverse the full length of Ithe cooler and emerge `at the opposite header 2l,

The inside surface of end Wall 44 is Shown in Figure 2 with a curvilinear section 41 where the end wall 44 merges with the back wall 38, In a similar way a curvilinear section 48 is made between back wall 38 and the partition 45. Opposed to the curvilinear sections 41 and 48, which vare concave, are the mutually and complementally curved convex surfaces 49 and 58 made between the external surfaces of the partition walls 5I and 52 and the connecting partition web 53. Thus the passage 46 is free of all angles, corners or obstructions which would tend to interfere with the free flow of the stream from the one tube to the other.

As shown in Figure 4 the passage 46 is in the upper half of the casting and is separated by a horizontal septum or partition 54 from a bottom passage 55 which connects tubes I1 and I9, as indicated in Figure 2. Reverting to Figure 4, the rear end of the horizontal partition 54 merges with the back wall 38 of the casting. The front wall of the horizontal partition 54 merges with the lower end of the vertical partition 53. The upper edge of the vertical partition 53 merges with the roof -36 of the casting. I

Again referring to Figure 2 and to Figure 7a, the lower passage 55 is shown as setting up connl munication between the intermediate tube I1 and the end tube I9. The end wall 56 forms part of this passage together with the rear wall 38 and an intermediate partition 51 shown in clotted lines in Figure 2 and in full lines in Figure '7a. This intermediate partition 51 as to height extends up from the bottom 36 only as highas the horizontal partition 54 with which its upper edge merges. Curvilinear sections 53 and 59 are formed in the passage 55 and curved convex surf faces 6I) and 6I are made opposite these sections on the corner portions of the partition 62. The partition 62 is shown in dotted lines in Figure 2 and in full lines in Figures 5 and '1a.V

The resultant of this construction is that crossover passages 46 and 5,5 are provided in the header 20 in which passage 46 is in the upper half of the casting and passage 55 in the lower half; passage 46 establishing communication between the ends of an end tube I6 and an intermediate tube I8, and passage 55 establishing communication between an intermediate tube I1 (companion of tube I6) and an end tube I9 (companion of tube I8).

In this way two tubes I6 and I1 carry the volume ow in one direction and two tubes I8 and I9 carry the volume flow in the o-pposite direction; in contrast to the single tube in the prior patented device for carrying the flow in each direction. In this way volumetric capacity may be greatly increased without increasing tube diameter sizes. The tubes may be retained of small diameter to lie closely against the hull thus formingminimum obstruction. v

Consequently the arrangement of tubes and headers forms a multiple l'low keel cooling system. The tube sockets of the header 20 are shown at 63, 64, 65 and 66, vsuch sockets receiving respectivelythetubes I6, I1, I8 and I9.

The header ZI at the opposite end of the cooler is formed precisely like the header 26 but is faced in the opposite directions so that its corresponding tube sockets 63a, 64a, 65e and 65a are reversed.

The arrangement of the passages is the same in both headers 28 and 2|. The upper cross-over passage 46EL in header ZI connects tubes IS and I1.; while the lower cross-over passage 55a con-` nects the tubes I8 and I6.

Screw clean-out plugs 61 and 69 are provided in the end wall 38 of eachheader at such spaced points that one plug will communicate with an upper passage 4S and, the other with a lower passage 55.

In operation7 hot water entering the cap 3A from the water jacket of the boat engine descends through the duct 39 at one side of the partition 30 in the stand pipe 2l and is directed by this duct 39 to the tubes i6 and Il', part of this incoming volume being absorbed by each of the two relatively small diameter tubes l5 and Il. These tubes also have greater external cooling surface exposed to the sea water than would one large tube of equal capacity. The divided hot fresh water thus flows in parallel masses in tubes 16 and Il in the direction of the arrows shown in Figure 2 until reaching left header 129 by which the direction of ow is reversed and the stream re-circulated in the opposite direction through tubes I8 and I9 completely across the device to the other header 2l, In this header 2| the diL rection of now is again reversed through 180 and the water circulated back through the other halves of tubes I6 and I l to the base fitting 20 and thence to the ascending or riser duct 49 to the right side of partition 30 in stand pipe 2l. Then the cooled water ascends into the cap 3d and is by this cap directed to the engine water jacket in a manner more fully described and shown in my prior patent previously referred to.

The device constitutes the multiple flow cooling system in which the mass of water to be cooled is split up and carried in two or more tubes in order to properly handle the volume.

When using a multiple flow system, the Velocity of the water which is carried through the tubes and which is guided to reverse directions by the terminal header fittings, assumes a parabolic action and iiows much faster in the outer tubes, thereby defeating the eiciency of the inner tubes. In other words the water in the inner tubes flows too lazily, with the result that the efficiency of the complete cooling system is upset. Because of this uneven flow a greater amount of tubing than would otherwise be required is necessitated.

The terminal header ttings constitute the mixing arrangement which has been developed in conjunction with the improved multiple ow cooling system by which the efliciency of the entire system is mantained at a maximum and the rate of flow of the water in the various tubes and headers is constant and uniform. The passages in the headers are split in such a way that the water from an outside tube is diverted to an inside tube. Through this arrangement, the momentum or parabolic action of the water is broken up, and its tendency to crowd the outer passages is overcome. All of the tubes therefore carry an even ow of water, which is very important in estimating their capacity of heat dissipation.

Thus the return or terminal fitting is cored in such a way that the water from an outer tube passes through a cored section over the water from an inner tube and is diverted to the inner tube on the return side. f Working from the other end this situation reverses itself.

In order to handle the large amount of circulating water it is absolutely necessary that the rection, spreading out and converging at the inlet andoutlet fitting. The terminal headers, due to their novel arrangement thoroughly mix the circulating water, thus achieving a substantially equal liow in all tubes which is of utmost irnportance for eicient operation.

Referring more particularly to Figures 10 to 13 inclusive, eight tubes are shown as against the four of the first form of the device. These eight tubes are arranged in parallel relation.. Four of the tubes marked 'l0 carry the water from the origin and terminal header ll to the Vaft header 'l2 in which the direction of current iiow is reversed and the water circulated back to header ll through the four tubes marked 13.

In this instance the stand pipe lll rises from the central portion of the origin and termial header 'll and its partition 'l5 diverts the incoming hot water to the tubes l0 and separates the same from the cooled eliiuent which is recirculated to the engine water jacket. The cap 'i6 also has partition ll forming a continuation of the partition l5. In Figure 12 the arrows show the incoming and outgoing water.

Figure 12 also shows the partition 15a extending outwardly as a prolongation of partitions 'i5 and ll into the base fitting i3 which in this instance is or may be a part of the origin and termin-al header ll. y

It is obvious that various changes :and modications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modications being restricted only by the scope of the following claim.

What is claimed is:

A cooling device comprising four tubes and headers connected to the ends of the tubes, each header comprising a casting cored out to provide rounded passages of approximately equal length, said passages overlapping vertically, a horizontal partition separating the passages, vertical partitions, one vertical partition extending from the top of the casting down to said horizontal partition, another vertical partition extending from the bottom of the casting up to said horizontal partition, tube sockets in the casting, the vertical partitions being in alinement with the intermediate tube sockets and being approximately one-half the cross-sections of the sockets, and other vertical partitions at substantially right angles to the first-named vertical partitions.

GUSTAVE WALTER.

REFERENCE S CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date -395,347 Pratt Jan. 1, 1889 1,000,310 Ward Aug 8, 1911 2,258,526 Walter Oct, 7, 1941 2,260,594 Young Oct. 28, 1941 2,356,844 Higgins Aug. 29, 1944 

